this code answers my question, but why? n->net_conf.tx_queue_size = MIN(virtio_net_max_tx_queue_size(n), n->net_conf.tx_queue_size); n->net_conf.tx_queue_size is 256 if peer->info->type != NET_CLIENT_DRIVER_VHOST_USER. At 2021-12-30 17:06:05, "longguang.yue" <libvirt@163.com> wrote:

Hi, all:

my environment is qemu-kvm-6.0.0, 4.18.0-240, libvirt 7.4.0. vm is configured like this queues='4' rx_queue_size='1024' tx_queue_size='1024'. inside vm i can not change nic's ring size. changing tx leads to error 'Cannot set device ring parameters: Operation not supported'. changing rx leads to error 'rx unmodified, ignoring. no ring parameters changed, aborting'

how to make it work and confirm what current value is?

thanks